1. Technical Field
The present invention relates to a liquid ejecting head unit and a liquid ejecting apparatus, and particularly, to an ink jet printing head unit and an ink jet printing apparatus which ejects ink as a liquid.
2. Related Art
A liquid ejecting apparatus which is represented by an ink jet printing apparatus such as an ink jet printer or a plotter includes a liquid ejecting head unit (hereinafter, referred to as a head unit) having plural liquid ejecting heads capable of ejecting a liquid such as ink stored in a cartridge or a tank in the form of a liquid droplet.
The plural liquid ejecting heads constituting the liquid ejecting head unit are highly precisely positioned and fixed to predetermined positions of a base plate as a common retaining member. That is, each of the liquid ejecting heads is fixed to the base plate while each nozzle is highly precisely positioned thereto. For example, each of the liquid ejecting heads is fixed to the base plate while the nozzles are highly precisely positioned thereto at the same pitch in a direction along a nozzle row formed by arranging in series plural nozzles of each of the liquid ejecting heads (for example, see JP-A-2006-231678).
However, since the base plate is expanded due to a variation in temperature of the head unit in use, each nozzle row of each liquid ejecting head is deviated from a desired predetermined arrangement position. Likewise, since the nozzle row is deviated from the desired predetermined arrangement position, a landing position where an ink droplet is landed on a printing medium such as a paper sheet is deviated, and hence a problem arises in that the printing quality deteriorates.
In addition, the problem exists in a liquid ejecting head unit for ejecting a liquid other than ink as well as the ink jet printing head unit.